1. Field of the Invention
This invention relates to a method of obtaining internal information of a measuring target to be investigated from the outside by the application of a nuclear magnetic resonance phenomenon. More particularly, the invention relates to a method of obtaining information on nuclear magnetic substances (such, for example, as H, F, Mg, Na, I, P and so on) disposed in specified areas in the body of a living or lifeless target mainly from the outside thereof by the application of the nuclear magnetic resonance phenomenon (hereinafter referred to as the NMR).
2. Description of the Prior Art
For this object, there has heretofore been proposed a method of using a nuclear magnetic resonance apparatus for measuring samples taken from specified areas of a measuring target or presuming the NMR properties of the specific areas, by measuring those of the whole target. Further, a method for measuring moving protons (such as blood flow) has also been considered in which the moving protons magnetized by a strong magnetic field established at a point upstream of the measuring point are measured in a homogeneous weak field.
Of these conventional methods, the first one has such defects that the measuring target is inevitably injured and that, in the case of a living thing, the sampling process inflicts pain on the lining target, and that since the samples are taken from the body, the measurements are carried out under different conditions from those in the body, resulting in errors.
For the presumption of the information on the specified areas from the whole measured value in accordance with the second method, it is necessary to clarify the correlation between the information of the measured areas and the whole. For example, in the case of detecting an abnormality within a living body, conditions therein with this method are too complicated to make this presumption.
The third method is apparently applicable only to moving protons and cannot be used for obtaining information on stationary protons. Further, this method has a problem to solve, that is, to provide a method of quantization in a living body or the like where corrections are extremely difficult.